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140 lines
3.2 KiB
140 lines
3.2 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Generic Syscon LEDs Driver |
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* |
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* Copyright (c) 2014, Linaro Limited |
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* Author: Linus Walleij <[email protected]> |
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*/ |
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#include <linux/io.h> |
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#include <linux/init.h> |
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#include <linux/of_device.h> |
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#include <linux/of_address.h> |
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#include <linux/platform_device.h> |
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#include <linux/stat.h> |
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#include <linux/slab.h> |
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#include <linux/mfd/syscon.h> |
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#include <linux/regmap.h> |
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#include <linux/leds.h> |
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/** |
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* struct syscon_led - state container for syscon based LEDs |
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* @cdev: LED class device for this LED |
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* @map: regmap to access the syscon device backing this LED |
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* @offset: the offset into the syscon regmap for the LED register |
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* @mask: the bit in the register corresponding to the LED |
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* @state: current state of the LED |
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*/ |
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struct syscon_led { |
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struct led_classdev cdev; |
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struct regmap *map; |
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u32 offset; |
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u32 mask; |
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bool state; |
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}; |
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static void syscon_led_set(struct led_classdev *led_cdev, |
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enum led_brightness value) |
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{ |
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struct syscon_led *sled = |
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container_of(led_cdev, struct syscon_led, cdev); |
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u32 val; |
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int ret; |
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if (value == LED_OFF) { |
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val = 0; |
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sled->state = false; |
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} else { |
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val = sled->mask; |
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sled->state = true; |
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} |
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ret = regmap_update_bits(sled->map, sled->offset, sled->mask, val); |
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if (ret < 0) |
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dev_err(sled->cdev.dev, "error updating LED status\n"); |
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} |
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static int syscon_led_probe(struct platform_device *pdev) |
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{ |
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struct led_init_data init_data = {}; |
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struct device *dev = &pdev->dev; |
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struct device_node *np = dev_of_node(dev); |
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struct device *parent; |
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struct regmap *map; |
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struct syscon_led *sled; |
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const char *state; |
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int ret; |
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parent = dev->parent; |
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if (!parent) { |
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dev_err(dev, "no parent for syscon LED\n"); |
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return -ENODEV; |
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} |
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map = syscon_node_to_regmap(dev_of_node(parent)); |
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if (IS_ERR(map)) { |
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dev_err(dev, "no regmap for syscon LED parent\n"); |
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return PTR_ERR(map); |
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} |
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sled = devm_kzalloc(dev, sizeof(*sled), GFP_KERNEL); |
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if (!sled) |
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return -ENOMEM; |
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sled->map = map; |
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if (of_property_read_u32(np, "offset", &sled->offset)) |
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return -EINVAL; |
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if (of_property_read_u32(np, "mask", &sled->mask)) |
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return -EINVAL; |
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state = of_get_property(np, "default-state", NULL); |
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if (state) { |
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if (!strcmp(state, "keep")) { |
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u32 val; |
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ret = regmap_read(map, sled->offset, &val); |
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if (ret < 0) |
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return ret; |
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sled->state = !!(val & sled->mask); |
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} else if (!strcmp(state, "on")) { |
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sled->state = true; |
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ret = regmap_update_bits(map, sled->offset, |
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sled->mask, |
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sled->mask); |
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if (ret < 0) |
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return ret; |
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} else { |
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sled->state = false; |
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ret = regmap_update_bits(map, sled->offset, |
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sled->mask, 0); |
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if (ret < 0) |
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return ret; |
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} |
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} |
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sled->cdev.brightness_set = syscon_led_set; |
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init_data.fwnode = of_fwnode_handle(np); |
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ret = devm_led_classdev_register_ext(dev, &sled->cdev, &init_data); |
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if (ret < 0) |
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return ret; |
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platform_set_drvdata(pdev, sled); |
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dev_info(dev, "registered LED %s\n", sled->cdev.name); |
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return 0; |
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} |
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static const struct of_device_id of_syscon_leds_match[] = { |
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{ .compatible = "register-bit-led", }, |
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{}, |
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}; |
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static struct platform_driver syscon_led_driver = { |
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.probe = syscon_led_probe, |
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.driver = { |
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.name = "leds-syscon", |
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.of_match_table = of_syscon_leds_match, |
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.suppress_bind_attrs = true, |
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}, |
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}; |
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builtin_platform_driver(syscon_led_driver);
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